Process of producing aldehyde sulfoxylates.



F. RIETHOF.

PROCESS OF PRODUCING ALDEHYDE SULFOXYLATES. APPLICATION FILED MAY 26,1910.

1,006,793 Patented 001;. 24, 1911.

FRANZ RIETHOF, OF'TEPLITZ-THURN', AUSTRIA-HUN GARY, ASSIGNOR TO THE FIRM F BLUMBERG & RINDSKOPF, OF ZUCKMANTEL,

NEAR TEPLITZ, AUSTRIA-HUNGARY.

rnocnss or PRODUCING ALDEHYDE SULFOXYLATES. I

To allwlzom'it'mag concern:

Be "it known that I, FRANZ RIETHOF, a .cltlzen of the AUSt1'0H11I1g2LI1:LI1 Empire,

and residing at Teplitz-Thurn, in said Em-.

pire of Austria-Hungary, have invented certain newand useful Improvements 1n Processes of Producing Aldehyde Sulfoxylates,

of which the following is a specification.

1 The formation of. formaldehyde sulphoxyli'c acid salts by the action of zinc dust on a solution of formaldehyde bisulfite in water is effected, as is well known,.only but j in an incomplete degree at normal temperature without the aid of heat. Better results areobtained by the process according to the German Patent No. 202242 in which process formaldehyde, bisulfite and zinc dust are permitted to react uponeach other at boiling heat, for which purpose they are either boiled for several hours, or heated for a longer time at a lower temperature.

According to the presentinvention it. is.-

- possible to complete this reaction in a much quicker, simpler and more rational manner without any external heating, by permitting formaldehyde bisulfite and zinc dust to react upon each other under pressure, preferably in the presence of, inactive or reducing gases, in which case theheat due to the reaction itself sufiices, together with a-corresponding pressure, to complete the reaction in a shorter period than is the case with the application of. boiling heatat normal pressure. In ge 'eral the greater the pressure applied,ythemore rapidly thereaction is effected. It is possible in'this manner to obtain' the reaction without external heating andin 'a far shorter time than has been possible hitherto, and yet to obtain an equally-good product.

e accompanying drawing shows one form of apparatus in which the improved process of producing aldehyde-sulfoxylates may be carried out.

It is self evident that in place of zinc dust, .iron powder or any other metallic reducing agent of equal value may be used. vSimilarly, instead of formaldehyde, 'benzaldehyde or any other saturated aldehyde may be used.

For the preparation of sodium ald'ehydesulfoxylates, it is possible to startwith sodium bisulfite, and then evaporating, preferably in a vacuum, the solution which is ob Specification of Letters Patent. Patented 001;, 24 1911. Application filed May 20, 1910. Serial. No. 562,352..

and which has been filtered to remove the Example: 100 partsof sodium bisulfite solution at 38 Be. are mixed in a digester a provided with a-stirring arrangement 6, as shown in .the drawing, with 25 parts-of 40% formaldehyde and 50 parts of zinc dust. Carbonic acid or other gas is then introduced through the opening 0 or otherwise and after the air has been displaced this mixture is, submitted to a pressure of. 6-8 atmospheres. A .pipe d from a proper source of supply may be connected with said opening 0 for introducing said gas and said gas may be under regulable pressure at its source of supply whereby the required pressure may be obtained inthe digester. Thedigester is provided with a man-hole e for introducing the reagent. The result of the mixing of the bisulfite solution and of the formaldehyde is a gradual rise of temperature of about 2530.' By a'simultaneous .mixing of'bisulfite solution with formaldehyde andzinc dust, the temperature of .the m xture rises about45'50. V With the pressure stated abpve the reactlon is effected without any heat in less thanan hour. In aseries of trials, the filtrate of the-reaction mixture.

showed a reduction-value of 9597 after a treatment. lasting 20 minutes at a pressure of' 6 atmospheres, as compared with a reduction value of 23, when the same mixture was stirred for two hours in an open vessel without pressure. In the above comparison the filtrate obtained according to the German Patent No. 202242 by boiling the mixture for two hours is taken as 100. The subsequent treatment of the product of reaction obtained by the new process is effected in the usual well-known manner.

I claim: 1. The process herein described of producing aldehyde-sulfoxylates which consists in mixing together "a metallic reducing, medium, an aldehyde, a bisulfite and water and application of.

The following in causing these substances to react upon each other under pressure."

2. The process herein described of producing aldehyde-sulioxylates which consists in mixing together a metallic reducing medium, an aldehyde, a bisulfite and water and in causing these substances to react upon each other under pressure in the presence of gases that prevent the oxidation of the products.

3. The process herein described. of pro- 'ducing sodium aldehyde-sulfoxylates, which consists in mixing together zinc dust, formaldehyde, sodium bisulfite and Water, and in causing these substances to react upon each other under pressure.

4. The process herein described of producing so'dium aldehyde-su1foxy1ates, which consists in mixing together zinc dust, formaldehyde, sodium bisulfite and Water, and in causing these substances to react upon each other under pressure in the presence of gases that prevent the oxidation of the products. I a

i In testimony, that I claim the foregoing as my invention, I have signed my name in presence of two subscribing-witnesses.

FRANZ RIETHOF.

Witnesses:

I ADOLPHE FIsoHER,-, H. H. S. BATE. 

